Explaining Plants in the Nightshade Family

Plants hold many secrets. They are living things that fight to survive in their environment and have natural defense systems. Some of these defenses include the production of chemicals that can be dangerous if ingested by humans and animals. Nightshade plants are a part of a regular diet for many animals and humans, but certain parts of them are not edible. The toxins can cause a range of issues including gastrointestinal upset, neurological symptoms, and even death. Learn how to stay safe when consuming or growing plants in the nightshade family.

Identifying Nightshades

Nightshade plants have on major similarity. All have a “hat” where the fruit connects to the plant. Some common nightshades are tomatoes, peppers, and eggplant. Potatoes cause the most issues, as they can sprout or turn green, causing them to become poisonous. Tobacco is also considered a nightshade, and it is the only one where the leaf is used. The leaves on others can be poisonous. Other than potatoes and tobacco, humans and animals alike eat the fruit of the plant. Some plants that are not considered nightshades also contain the same compound that causes problems for humans and pets include sugar beets, apples, and cherries. These items also contain glycoalkaloids. In all, there are over 2,800 species of plants that fall into the nightshade family.


Glycoalkaloids are what make these plants so dangerous. These compounds, however, are meant to protect the plants. They are naturally produced pesticides. These plants are protected from fungi, bacteria, insects, and viruses. Glycoalkaloids are mostly found in the flowers, leaves, and fruits that have not ripened. They are also found in all areas of the plant, even the part we eat.

These compounds work by binding to cholesterol in the cell membrane. The cells erupt or leak in response to the disruption of their structure. They basically form little explosions in the body of the person or animal that consumes them. They are also known to be neurotoxins. The enzyme cholinesterase is blocked by glycoalkaloids. Acetylcholine is an important neurotransmitter that helps bring messages from nerves to muscle cells. Glycoalkaloids breaks this down and disrupts proper transmission. This causes the acetylcholine to reach an amount that is too high for the system to handle. This is similar to how nerve gasses work. The results can cause victims to experience convulsions, respiratory arrest, and paralysis. Death can also occur in cases of extreme exposure.


These plants can cause dangers to pets if you have them growing in your yard. Dogs, especially, like to snack on plants. They often do not discern the dangers and eat the greenery of nightshades. Compost piles in the backyard can also host these toxins and many others.  Humans run into problems mainly with potatoes. Old potatoes, or those that have been stored improperly tend to sprout. These sprouts can contain dangerous levels of glycoalkaloids. In small amounts, many people may not notice any effects. After all, we often eat these foods daily. It is a theory, however, that some people are more sensitive than others to these items. Many people do not know this until they remove the foods from their diet. Lab animals have shown to present with birth defects after ingesting large amounts. It should be considered that these are smaller animals that are meant to be deterred from eating the plants.

There has also been some concern over mental effects of glycoalkaloids. Since they are a neurotoxin, this has been taken into consideration. They can cause hallucinations and may have an effect on anxiety and other mental health issues. One particular incident involved some old potatoes that were served to a group of school boys in England. Many of the boys ended up in the hospital with gastrointestinal complications. The worst cases involved change in mental status. Cognitive abilities were impaired, and hallucinations took place.

Nightshades are group of plants that naturally protect themselves from the environment and predators. Glycoalkaloids are known to be dangerous in high doses. Care should be taken to dispose of foods that are not in good condition, and to let them ripen properly. Nightshades should be kept out of the reach of pets while they are growing in the yard, as well. Careful attention to your food products can prevent issues.

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